首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   2393789篇
  免费   185152篇
  国内免费   4877篇
耳鼻咽喉   33596篇
儿科学   79627篇
妇产科学   69152篇
基础医学   345202篇
口腔科学   66639篇
临床医学   211892篇
内科学   469821篇
皮肤病学   53627篇
神经病学   192011篇
特种医学   92219篇
外国民族医学   793篇
外科学   364696篇
综合类   54056篇
现状与发展   4篇
一般理论   742篇
预防医学   184321篇
眼科学   55340篇
药学   175446篇
  2篇
中国医学   5204篇
肿瘤学   129428篇
  2018年   25322篇
  2017年   19248篇
  2016年   21821篇
  2015年   24706篇
  2014年   34650篇
  2013年   51951篇
  2012年   70518篇
  2011年   75171篇
  2010年   44506篇
  2009年   42283篇
  2008年   70820篇
  2007年   75699篇
  2006年   76752篇
  2005年   74629篇
  2004年   71733篇
  2003年   68796篇
  2002年   67204篇
  2001年   113239篇
  2000年   115945篇
  1999年   97362篇
  1998年   27878篇
  1997年   25147篇
  1996年   25258篇
  1995年   23952篇
  1994年   22055篇
  1993年   20729篇
  1992年   75874篇
  1991年   73526篇
  1990年   71645篇
  1989年   69090篇
  1988年   63790篇
  1987年   62524篇
  1986年   59013篇
  1985年   56314篇
  1984年   42523篇
  1983年   36483篇
  1982年   21976篇
  1981年   19536篇
  1979年   38933篇
  1978年   27573篇
  1977年   23275篇
  1976年   22111篇
  1975年   23600篇
  1974年   28080篇
  1973年   27070篇
  1972年   25580篇
  1971年   23541篇
  1970年   22164篇
  1969年   20984篇
  1968年   19729篇
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
71.
AimsWe previously showed that the protective effects of endothelial progenitor cells (EPCs)‐released exosomes (EPC‐EXs) on endothelium in diabetes. However, whether EPC‐EXs are protective in diabetic ischemic stroke is unknown. Here, we investigated the effects of EPC‐EXs on diabetic stroke mice and tested whether miR‐126 enriched EPC‐EXs (EPC‐EXsmiR126) have enhanced efficacy.MethodsThe db/db mice subjected to ischemic stroke were intravenously administrated with EPC‐EXs 2 hours after ischemic stroke. The infarct volume, cerebral microvascular density (MVD), cerebral blood flow (CBF), neurological function, angiogenesis and neurogenesis, and levels of cleaved caspase‐3, miR‐126, and VEGFR2 were measured on day 2 and 14.ResultsWe found that (a) injected EPC‐EXs merged with brain endothelial cells, neurons, astrocytes, and microglia in the peri‐infarct area; (b) EPC‐EXsmiR126 were more effective than EPC‐EXs in decreasing infarct size and increasing CBF and MVD, and in promoting angiogenesis and neurogenesis as well as neurological functional recovery; (c) These effects were accompanied with downregulated cleaved caspase‐3 on day 2 and vascular endothelial growth factor receptor 2 (VEGFR2) upregulation till day 14.ConclusionOur results indicate that enrichment of miR126 enhanced the therapeutic efficacy of EPC‐EXs on diabetic ischemic stroke by attenuating acute injury and promoting neurological function recovery.  相似文献   
72.
73.

Researchers have highlighted numerous sociocultural factors that have been shown to underpin human appearance enhancement practices, including the influence of peers, family, the media, and sexual objectification. Fewer scholars have approached appearance enhancement from an evolutionary perspective or considered how sociocultural factors interact with evolved psychology to produce appearance enhancement behavior. Following others, we argue that evidence from the field of evolutionary psychology can complement existing sociocultural models by yielding unique insight into the historical and cross-cultural ubiquity of competition over aspects of physical appearance to embody what is desired by potential mates. An evolutionary lens can help to make sense of reliable sex and individual differences that impact appearance enhancement, as well as the context-dependent nature of putative adaptations that function to increase physical attractiveness. In the current review, appearance enhancement is described as a self-promotion strategy used to enhance reproductive success by rendering oneself more attractive than rivals to mates, thereby increasing one’s mate value. The varied ways in which humans enhance their appearance are described, as well as the divergent tactics used by women and men to augment their appearance, which correspond to the preferences of opposite-sex mates in a heterosexual context. Evolutionarily relevant individual differences and contextual factors that vary predictably with appearance enhancement behavior are also discussed. The complementarity of sociocultural and evolutionary perspectives is emphasized and recommended avenues for future interdisciplinary research are provided for scholars interested in studying appearance enhancement behavior.

  相似文献   
74.
75.
76.
77.
78.
79.
80.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号